(a) Field of the Invention
The present invention relates to methods for identifying the plurality of aptamers that bind to different sites of a target molecule and methods for using the same. In particular, the plurality of aptamers binding to different sites of the target molecules is identified from a library of aptamers identified from the same SELEX process.
(b) Description of the Related Art
Aptamers are useful in a wide variety of diagnostic applications including in two site binding assays such as sandwich Enzyme liked immunosorbent assay (ELISA). A sandwich type assay using aptamers requires two different aptamers that recognize different binding site of target molecules. Sandwich type assays are highly specific and sensitive, and therefore are useful as a diagnostic tool and are often used in a wide variety of research and clinical settings. Unfortunately, there is no method for readily identifying two aptamers needed in a sandwich type assay. In fact, most sandwich type assays use only one aptamers, if at all, and an antibody or a protein as a complementary unit for a sandwich type assay. This is mainly due to a difficulty in finding two different aptamers that bind to two different site of a protein or a target biological moiety.
Therefore, there is a need for a method for identifying two different aptamers that are needed in a sandwich type assay.